(1) Field of The Invention
This invention relates to lead-acid cells or batteries and particularly to the provision of a battery container (or case) in which the jar and lid are sealingly joined without the need for placement of the combination in a fixture for curing or hardening of the substance affixing the lid to the jar.
Battery cases are commonly made of engineering plastic material which is resistant to sulfuric acid, including Noryl.RTM. (polyphenylene oxide), ABS, polypropylene, and the like; and they include at least a jar where the plates, separators, and acid reside and a lid which is sealingly joined to the jar. Typically, sulfuric acid resistant epoxy is used to join the lid to the jar. The epoxies that are adequately effective at maintaining the joint are slow cure epoxies that typically take 4-6 hours to cure to a handling state and 16-20 hours for a full cure.
During cure, the hydraulic force produced by the epoxy, as well as other forces, are enough to cause the lid to partially separate from the jar, disrupting the seal. Even when the battery is left to cure inverted with the entire weight of the jar and all components contained within weighing upon the joint, the seal maybe disrupted by separation caused by the hydraulic and other forces.
(2) Description of The Prior Art
To overcome this problem the battery container is typically placed in a fixture, after the epoxy is applied to the region to be joined, and allowed to stand undisturbed until an adequate state of cure is reached that allows safe handling of the battery. Such fixturing adds expense in the production of the battery by requiring more equipment in the production line (the fixture and any equipment used in applying and removing the fixture), increasing complexity of assembly and increasing either labor or machine time during production.